I recently bought a f90bt from my friend 12" rockford sub a weird branded amp for speakers and a kicker amp for sub....they installed it which cost me about $100 and another $40 some misc. Crap which i didnt even need because it came with all the wiring.....when i bump my music up the sub hits hard then it stops dead then the sub turns back on and hits for a couple of seconds then stops it only happens when i turn up the volume... And also now when i fade my speakers to front it goes to the back when i fade to the left it goes to the right vice versa...... Any body have any idea about my sub? I think i can get the fade to work with rewiring but im stumped on the subwoofer part...?

 

sounds like clipping to me, they probably have the gain set to high. This is not good for the sub or amp at all, it will kill them fast. You are suppose to tune the amp at a certain set volume on the headunit, you tune it at that level so there is no distortion or clipping, then you aren't suppose to go passed that volume.

 

Yea thats what i did actually i got in my car took my seats down their mounted behind my back seats i turned my deck to around 45 thats the highest i usually go.. then turned down the freq all the way turned up bass boost halfway then turned up my gain like 1/3 of the way and listened and no distortion ... so as long as i stay under 45 it would be fine right?... and i also do have another question.. on the f90bt i don tknow if anyone is familiar but the hpf i think it is suppose to turn the gain on the front speakers thats what my friend told me but when i turn it off my sub hits like 3 times harder when i turn it to like 125 hertz the sub gets lower back to normal bass..and when i turn up the level of subwoofer nothing happens when i turn up bass boost from deck nothing happens.. when i turn off my sub from the deck it doesnt turn off seems like the only way to control the sub is from my amp... it doesn tmake any sense?

 

yea if you tuned it for that level then you should be fine with anything under that.

Im not sure about the other stuff, sounds like they spliced in the front speakers on something.

this doesnt surprise me because they messed up my 4 channel amp install on my old car. They didnt even run speaker wire to the front, the just spliced into the factory wiring some how so it caused a big mess after a month or so.

 

hmm what do you think the problem is with not being able to turn off my sub from the deck could it be the wiring ? the remote wire on back of deck?

 

Is your "weird amp" a 2 channel or 4 channel amp, and what brand? If it's 4 channel, then they wired the RCAs incorrectly. It's not an uncommon problem, even in the very good shops (but they catch it and correct it before you get the car back). Your Kicker sub amp should be initially set with the bass boost flat, low pass crossover frequency at about 80-100hz. Any higher and it swamps your midbass in your 6" speakers and forces your 12" to play what it doesn't like.
1. Start off by turning your main speaker amp gain to zero, turn your headunit volume to about 75%. Then turn up your main amp gain until you get a very slight distortion, then back it down bit.
2. Now repeat the procedure with the Kicker sub amp (amp gain @0, HU volume 75%, bring up amp just until distortion, back it down).

This sets your initial gain structure for both amps. Once that is done, now you begin to balance your main speaker and sub levels. Most likely, either the sub or your mains are too loud for the other.

If the mains are too loud for the subs, lower their amp's gain. If the sub's too loud, lower it's gain. Go for a clean transition of sound from main speakers to sub.

IF you don't feel comfortable doing this, find a reputable independent car stereo shop and ask them to adjust the system. Independent shops usually charge for the service, but then they back up their service too.

 

Interesting - A bit off topic but - I have a f90bt and adjusting the gains and bass to me seems difficult and the equalizer bands are group into sets and its a bid hard to "ungroup" them in the setting...sounds confusing...but it takes a while to get used to

My Sony amp did the same thing as above, it would play for a few seconds kick well and shut off, after many attempts to correct the issue I just bought another amp and so far so good, but with the f90bt bass adjustment is a must.

You may want to check out the AVIC forum at http://avic411.com/

they have a section for the F90BT thats how I learn to play with my system

As always you have great people here with great knowledge and with good advice.

Good Luck! Hope you dont have to buy another amp, my amp powers on and stuff but cant seem to get it to stay on...but with other amps i tried it works fine so F it i moved on

 

too low ohm load for the amp, poor ground, amp is damaged

 

how about before you bash best buy you bring it back to them to fix. I'm tired of people like you bashing Best Buy when you dont go back to them telling them about a problem. I have been installing for more years than you can think and I am an excellent installer there. Been like that for many years and if you told me these problems and I installed it, I would have you come right back in.

Talk to your installer, but before you blame him give him another shot. And remember, you bought those things second hand.

 

^^well just because you are a good one doesnt mean there arent bad ones. It took 5 attempts for them to fix the problems they caused with my system in my old car. I bought everything from them new and they couldnt even hook it up right. Took it to another best buy while i was at school and the guy said it looked like a 3 yr old wired everything. Then he didnt even fix right. That is why i learned and started doing all of this stuff myself.

but yea he should bring it back and make them fix it.

 

just never jump to conclusions. Of course I have messed up a couple cars in my times and learned. I just hate when people put down an entire company because of one person.

 

i thanks for the knowledge..i have done step 1 and 2 and it sounds a lot better now.. but back to the other question where i cant turn off my sub cant turn it up and down on my deck i believe you said it is the rca..and yes the weird amp is a 4 channel. do you know how its suppose to be set up? so i can look into we wiring it?

 

i dont mean to talk down on best buy im calling all of them a bad installer but the 2 bestbuys i have been to have always seemed to mess up my system..